Although VGF knockout mice are smaller and thinner compared to their wild type littermates (Salton et al., 2000), TLPQ-21 was shown to induce anorexic effects, to activate lipolysis and modulate inflammatory pain, and to blunt obesity induced by diet (Bartolomucci et al., 2006, 2009; Rizzi et al., 2008). This evidence concerns the gene VGF and obesity due to melanocortin 4 receptor deficiency.